Many machines require fluid actuated motors such as piston and cylinder assemblies to move parts of the machine. Also, in many cases such as in individual section glassware making machines, the speed of movement of the machine part needs to be precisely controllable. In the forward movement of the machine part this is often called velocity control, and in the return stroke of the machine part this is often called cushioning control. In either case, it is a variable orifice adjustment of the needle valve which controls the restriction to the fluid flow, and, hence, controls the speed of movement of the machine part.
In the prior art such as in individual section glassware making machines, many such valve assemblies are required, for example, a gang of 21 such valve block assemblies may be mounted side by side for operation from the same air pressure source. In the past, to adjust the variable orifice fluid flow restriction, this needle valve adjustment was accomplished manually by an artisan who adjusted the throttling or cushioning in order to achieve a precise timed relationship of the machine part relative to the movements of all of the rest of the parts of the machine. In such glassware making machine it will be appreciated that there are many machine parts, all of which must be inter-related, for example, the gob feeder which feeds a gob of heated glass, the parison formation, the transfer to a blow mold station, the action of the molds including opening and closing of the parison and the blow molds, the take-away conveyor and so forth. In the prior art, these inter-related timed motions were controlled by a manually adjustable needle valve.
Such manual adjustment relied almost completely upon the skill of an artisan with long experience in order to operate the machine with a high degree of precision in the inter-related movements without a lot of broken glassware and scrap. The prior art glassware making machines typically operated at about 60 to 80 percent efficiency, the rest being scrap in one form or another and much of this was due to the fact that it was quite difficult to properly adjust the manually adjustable needle valves. Also, each time the machine was changed to make a different form of glassware, all of the ganged valve block assemblies had to be changed in their adjustments, and this was a long procedure in the setup before the machine was producing the new type of glassware at a satisfactory rate.
Accordingly, an object of the invention is to provide a motor-operated needle valve.
Another object of the invention is to provide an adjustable valve assembly wherein line shaft means is disposed transversely to the movement of a valve member and is connected to operate such valve member.
Another object of the invention is to provide a ganged valve assembly with a plurality of valve blocks each having a valve member operable from two line shafts extending transversely to the plurality of valve blocks.
Another object of the invention is to provide a valve assembly wherein first and second line shafts are provided for selectively actuating a valve member in opening and closing directions.
Another object of the invention is to provide an adjustable valve assembly with transverse line shaft means and first and second clutch means connecting the line shaft means to an adjustable valve member for opening and closing movements respectively.